#include <iostream>
#include <vector>

using namespace std;

int main(){
    vector<int> v{1,2,3,4,5,6,7,8,9};
    for(auto& i : v){
        i *= 2;
    }
    for(auto i : v){
        cout << i << ' ';
    }
    cout << endl;
    return 0;
}